In general, electric apparatuses of a vehicle may be classified into electric apparatuses of an engine side and electric apparatuses of a vehicle body side. The electric apparatuses of the engine side include an ignition system including an ignition coil, a distributor high voltage cable, an ignition plug, and the like, and a charging apparatus including a generator and a regulator. The electric apparatuses of the vehicle body side include a lamp system including a lamp system for lighting, a lamp system for signs, a lamp system for signal, an instrument alarm display installed on an instrument panel, an air-conditioner, and the like, including a storage battery. Such electric apparatuses of the vehicle are connected to an electronic control unit (ECU) by a wire within a vehicle engine room. A junction block may be used as an intermediate medium connecting the wire and the ECU to each other.
The junction block is a block in which a fuse, a relay, and the like disposed in the vehicle are configured into a single assembly. Further, the junction block is a series of structures for preventing an over-current from flowing in a variety of electric apparatuses wired in the vehicle in advance. The junction block includes the fuse, a variety of terminals, the relay, and the like installed therein. In addition, a high voltage connector connected to the fuse, the variety of terminals, the relay, and the like is connected to a lower portion of the junction block.
Meanwhile, since an electric vehicle uses a high voltage, a reduction in noise has been recently researched. Further, since the electric vehicle is additionally installed with various equipments for convenience, safety devices, etc. to meet the requirements of convenience and stability of consumers, a high-capacity power source is required. Accordingly, as a power distribution system of the electric vehicle, a power system which is gradually boosted from a power system of 14V to a power system of 36V or 42V to 48V has been researched and developed.
In the electric vehicle, when current terminals connecting power supply to the respective electronic units are inserted and separated, an arc discharge occurs in the range of various voltages. The occurrence of the arc discharge may cause an adverse effect on a driver, a passenger, a mechanic, and the like. When the power system of 42V, which is the high-voltage power system, is applied, the arc discharge occurring at the terminal or the others is more than several times as compared to the power system of 14V. In other words, when the arc discharge occurs at the power system of 42V, which is the high-voltage power system, a discharge voltage thereof is about 1000V or greater. As a result, a starting-off, and the like may occur due to terminal contact defectiveness by vibration during driving on a road.